The dam, built in 1918, crosses the Chicopee River in a roughly north-to-south direction, and is a concrete gravity structure approximately 223-foot long by 22-foot high.  The northern abutment of the dam is contiguous with the abutment for the Ludlow Avenue Bridge.  Adjacent to this abutment are a skimming gate with invert at El. 199.7 feet and a deep sluice gate with invert at El. 183.9 feet. The deck elevation at the two gates is El. 212.9 feet.  A 23-foot non-overflow section extends from the gate area to the 200-foot long ogee spillway which extends across the river to the south abutment, El. 212.9 feet.  A concrete retaining wall extends from the south abutment at El. 212.9 feet for approximately 133 feet.

At normal pond elevation the Putts Bridge Project impoundment extends approximately 3.3 miles upstream of the dam.  At normal pond condition, the maximum surface area is approximately 65 acres at El. 205.3’.  While the maximum useable storage of the reservoir is 323 acre-feet, the used storage capacity is just 65 acre-feet.  While the permitted daily drawdown is 1 foot during the spring and 2 foot for the balance of the year (except during energy audits and system emergencies when this limit may be exceeded), the actual year-round drawdown is 1 foot.

The concrete headgate structure is adjacent to the northeast abutment of the dam, and has a deck elevation of 212.9 feet.  Six motorized headgates, each approximately 12 feet wide by 13.3 feet high direct the flow to the underground concrete conduits that lead to the powerhouse forebay.  A double-barreled, underground concrete conduit extends 647 feet from the impoundment to the forebay.  Each barrel of the conduit is 16.5 feet high by 12.5 feet wide.

The forebay is a reinforced concrete structure measuring 40 feet wide by 104 feet long.  The forebay is 41.5 feet high, with a top elevation of 210.3 feet.  There is a 2.5-foot diameter spigot type drain gate at the base of the forebay, and an 18-foot wide skimming gate on the north forebay.

The trashrack is situated along the western forebay wall, extending from the floor of the forebay (El. 169.4 feet to El. 208.1 feet).  There is a mechanical trash rake mounted on rails along the entire width of the trashrack.  Wooden headgates, measuring 14.3 feet square, isolate the forebay from the generating units.

The Putts Bridge Project powerhouse has a concrete substructure with a brick superstructure.  It measures 45 feet wide by 154 feet long.  The structure houses the two operating units, No.2 and No.3, and one retired, No. 4.  Unit No.1 was never installed although the turbine pit is there.  Unit No.5 is a retired waterwheel exciter.  The normal tailrace elevation is 160.9 feet.  The tailrace canal runs 355 feet from the powerhouse in a westerly direction to where the flow re-enters the Chicopee River.

The powerhouse’s 11.5 KV generators are connected to 11.5 KV circuit breaker to a 4.5 MVA autotransformer located at WMECO’s North Street substation.  At the substation, the autotransformer steps the voltage up from 11.5 KV to 13.8 KV for interconnection to WMECO’s 13.8 KV distribution system.

The Putts Bridge project is situated upstream of three other hydroelectric facilities located on the Chicopee River and downstream of two other dams on the Chicopee River as well as other dams on the Ware, Swift and Quaboag Rivers. Two of the three downstream hydroelectric facilities are owned and operated by Central Rivers Power, MA – Dwight Station Project (P-10675) and Indian Orchard Project (P-10678).  The Red Bridge Project (P-10676) is located upstream and also owned and operated by Central Rivers Power, MA.  Immediately upstream of the Putts Bridge Project is Collins Dam Project (P-6544) and immediately upstream of Dwight Station Project is Chicopee Falls Dam (P-6522).

The Project and the other Central Rivers Power, MA dams on the Chicopee River have little to no control over their inflows.  Collins Hydro and Chicopee Falls dams are owned and operated by unrelated entities as are all of the hydroelectric projects on the upstream tributaries of the Chicopee River.

The Putts Bridge project is operated in a limited pond-and-release mode, utilizing the useable storage capacity (65 acre-feet) afforded by a 1.0 foot drawdown during the second quarter and 2.0 foot drawdown during the balance of the year. The station is operated semi-automatically by float controls.  The operating mode of the Putts Bridge project does not change during dry, mean or high water years.  As flows vary at the Project, the number of turbines operating and the duration of operation changes, increasing and decreasing the amount of generation realized.